#include<stdio.h>
#include<math.h>
#include<time.h>
#include<stdlib.h>
/*int main() {
	int a = 7 ;
	float x = 2.5;
	float y = 4.7;
	printf("%f\n ",x+a%3*(int)(x+y)%2/4);
	return 0;

	
}*/


/*int main()
{
	int b = 7;
	float a= 2.5;
	float c = 4.7 ;
	printf("%f",a+(int)(b/3*(int)(a+c)/2)%4);
	return 0;
	
}*/





 /*int main(){
 	int x=15;
 	double y;
 	y=sqrt(sin(15*3.14/180))/8/log10(2*3.14)+fabs(exp(2.5)-x);
 	printf("%f",y);
 	return 0;
 }*/
 
 
 int main(){
 	int a ,b, c;
 	unsigned int seed;
 	seed=(unsigned int)time(NULL);
 	srand(seed);
 	a=rand()%10+1;
 	b=rand()%10+1;
 	printf("%d+%d=",a,b);
 	scanf("%d",&c);
 	if(c==a+b)
 	printf("OK");
 	else
 	printf("error");
 	return 0;
 	
 }
